In the early 1960s the U.S.S.R. had learned that NATO's innovations in armor had rendered the Soviet T-55 tank obsolete. Their answer came swiftly with the introduction of the T-62 main battle tank. As the first tank was manufactured with a smoothbore barrel, it was capable of firing kinetic energy penetrating rounds that could pierce the latest NATO armor. Later versions of the T-62 were equipped with explosive reactive armor (ERA), which uses small detonations to disrupt armor-penetrating rounds at the moment of impact. This long-lived tank featured prominently in the Yom Kippur War, Iran-Iraq War, and Gulf Wars, and it continues to serve in many Middle Eastern and North African militaries.